Computer- and Robot-assisted Resection of Thalamic Astrocytomas in Children

Neurosurgery ◽  
1991 ◽  
Vol 29 (1) ◽  
pp. 27-33 ◽  
Author(s):  
James M. Drake ◽  
Michael Joy ◽  
Andrew Goldenberg ◽  
David Kreindler

Abstract Six children ranging in age from 2 to 10 years who harbored deep benign astrocytomas were operated upon using a computer- and robot-assisted system. A radical excision was achieved in all cases with no significant morbidity nor any mortality. The system consists of an interactive, three-dimensional display of computed tomographic image contours and digitized cerebral angiograms taken using the Brown-Roberts-Wells stereotactic frame. The surgical retractor is held and manipulated using a PUMA 200 robot. The position and orientation of the surgical retractor is displayed on the three-dimensional display. Preoperative planning and simulation are important features of this system. Movement of the brain after removal of the tumor and cerebrospinal fluid is substantial, so the tumor removal is based on visually defined margins. Enhanced computer graphics and robotic devices are important adjuncts to neurosurgical procedures and will find increasing use in the future. (Neurosurgery 29:27-31, 1991)

Neurosurgery ◽  
1991 ◽  
Vol 28 (6) ◽  
pp. 792-800 ◽  
Author(s):  
Eiju Watanabe ◽  
Yoshiaki Mayanagi ◽  
Yukio Kosugi ◽  
Shinya Manaka ◽  
Kintomo Takakura

Abstract A new computed tomographic-stereotactic device that translates the operating point onto preoperative computed tomographic (CT) images, the Neuronavigator, has been developed. We have applied this system to various neurosurgical procedures to examine its usefulness. The system consists of a 6-joint sensing arm and a 16-bit personal computer. It projects the location of the arm tip onto a corresponding CT slice with a cursor that guides the surgeon toward the intracranial target during open surgery. The system also projects the location of the tip onto angiograms, and when used in conjunction with echography or a transcranial Doppler (TCD) flow meter, the surgeon's ability to navigate is enhanced. Sixty-eight patients underwent operation with the Neuronavigator. The navigation system worked as the core of a multimodal three-dimensional data base that proved to be useful during surgery. The maximum detection error was 2.5 mm, which was considered sufficient for open microsurgery. It also proved useful in designing the position of a craniotomy, in targeting deep-seated mass lesions, and in tracing the tumor edge, which had been identified on a CT scan. When the angiogram was combined with the navigator, it became easy to identify key vessels within a small operating field. The system was also combined with a TCD flow meter. This combination makes it possible to translate the measuring point of the TCD directly into CT coordinates, improving the precision of location of the TCD probe. The Neuronavigator combines various diagnostic images into one database and effectively guides the surgeon during surgery.


Author(s):  
Ted Janssen ◽  
Gervais Chapuis ◽  
Marc de Boissieu

The law of rational indices to describe crystal faces was one of the most fundamental law of crystallography and is strongly linked to the three-dimensional periodicity of solids. This chapter describes how this fundamental law has to be revised and generalized in order to include the structures of aperiodic crystals. The generalization consists in using for each face a number of integers, with the number corresponding to the rank of the structure, that is, the number of integer indices necessary to characterize each of the diffracted intensities generated by the aperiodic system. A series of examples including incommensurate multiferroics, icosahedral crystals, and decagonal quaiscrystals illustrates this topic. Aperiodicity is also encountered in surfaces where the same generalization can be applied. The chapter discusses aperiodic crystal morphology, including icosahedral quasicrystal morphology, decagonal quasicrystal morphology, and aperiodic crystal surfaces; magnetic quasiperiodic systems; aperiodic photonic crystals; mesoscopic quasicrystals, and the mineral calaverite.


Author(s):  
Honglei Xu ◽  
Linhuan Wang

In order to improve the accuracy of dynamic detection of wind field in the three-dimensional display space, system software is carried out on the actual scene and corresponding airborne radar observation information data, and the particle swarm algorithm fuzzy logic algorithm is introduced into the wind field dynamic simulation process in three-dimensional display space, to analyze the error of the filtering result in detail, to process the hurricane Lily Doppler radar measurement data with the optimal adaptive filtering according to the error data. The three-dimensional wind field synchronous measurement data obtained by filtering was compared with three-dimensional wind field synchronous measurement data of the GPS dropsonde in this experiment, the sea surface wind field measurement data of the multi-band microwave radiometer, and the wind field data at aircraft altitude.


2020 ◽  
Vol 34 (03) ◽  
pp. 145-151
Author(s):  
Shimpei Ono ◽  
Hiroyuki Ohi ◽  
Rei Ogawa

AbstractSince propeller flaps are elevated as island flaps and most often nourished by a single perforator nearby the defect, it is challenging to change the flap design intraoperatively when a reliable perforator cannot be found where expected to exist. Thus, accurate preoperative mapping of perforators is essential in the safe planning of propeller flaps. Various methods have been reported so far: (1) handheld acoustic Doppler sonography (ADS), (2) color duplex sonography (CDS), (3) perforator computed tomographic angiography (P-CTA), and (4) magnetic resonance angiography (MRA). To facilitate the preoperative perforator assessment, P-CTA is currently considered as the gold standard imaging tool in revealing the three-dimensional anatomical details of perforators precisely. Nevertheless, ADS remains the most widely used tool due to its low cost, faster learning, and ease of use despite an undesirable number of false-positive results. CDS can provide hemodynamic characteristics of the perforator and is a valid and safer alternative particularly in patients in whom ionizing radiation and/or contrast exposure should be limited. Although MRA is less accurate in detecting smaller perforators of caliber less than 1.0 mm and the intramuscular course of perforators at the present time, MRA is expected to improve in the future due to the recent developments in technology, making it as accurate as P-CTA. Moreover, it provides the advantage of being radiation-free with fewer contrast reactions.


2020 ◽  
Vol 461 ◽  
pp. 125260 ◽  
Author(s):  
Peng Sun ◽  
Chenning Tao ◽  
Jinlei Zhang ◽  
Rengmao Wu ◽  
Siqi Liu ◽  
...  

2021 ◽  
Vol 52 (S1) ◽  
pp. 613-616
Author(s):  
Gewei Yan ◽  
Jiayi Li ◽  
Chenxi Zhao ◽  
Zengxiang Lu ◽  
Zhaojun Liu

Sign in / Sign up

Export Citation Format

Share Document